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ptx
This version of ptx
contains a few features which do not exist in
System V ptx
. These extra features are suppressed by using the
-G
command line option, unless overridden by other command line
options. Some GNU extensions cannot be recovered by overriding, so the
simple rule is to avoid -G
if you care about GNU extensions.
Here are the differences between this program and System V ptx
.
This program can read many input files at once, it always writes the
resulting concordance on standard output. On the other hand, System V
ptx
reads only one file and sends the result to standard output
or, if a second file
parameter is given on the command, to that
file
.
Having output parameters not introduced by options is a dangerous
practice which GNU avoids as far as possible. So, for using ptx
portably between GNU and System V, you should always use it with a
single input file, and always expect the result on standard output. You
might also want to automatically configure in a -G
option to
ptx
calls in products using ptx
, if the configurator finds
that the installed ptx
accepts -G
.
ptx
are options -b
,
-f
, -g
, -i
, -o
, -r
, -t
and
-w
. All other options are GNU extensions and are not repeated in
this enumeration. Moreover, some options have a slightly different
meaning when GNU extensions are enabled, as explained below.troff
or
nroff
. It is rather formatted for a dumb terminal. troff
or nroff
output may still be selected through option -O
.-R
option is used, the maximum reference width is
subtracted from the total output line width. With GNU extensions
disabled, width of references is not taken into account in the output
line width computations.ptx
does not accept 8-bit
characters, a few control characters are rejected, and the tilde
‘~
’ is also rejected.ptx
processes only
the first 200 characters in each line.ptx
,
but still, there are some slight disposition glitches this program does
not completely reproduce.ptx
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